Impedances, and particularly resistors as generally manufactured, include two indications; one indication is of a nominal value while the second indicates the tolerance of the impedance from the nominal value. Tolerance actually is an indication of the tolerable percent error of the impedance value from the nominal value, and therefore, is indicated in percentage, e.g., 5%, 10%, etc.
One prior art apparatus and method for determining the tolerance of an impedance includes a Wheatstone bridge as an impedance measuring device. However, the use of a Wheatstone bridge is relatively time consuming when it is necessary to monitor the exact value of many impedances used for industrial purposes. Because it is necessary to monitor the value of many impedances for industrial purposes, it is desirable to reduce the measuring time to determine the tolerance of the impedance and to simplify the steps required by an operator to determine if the impedances have the desired tolerance. With the prior art techniques, it is necessary for an operator to frequently adjust the bridge to determine each particular impedance tolerance measurement.